Simply the book on your classic boxer
BMW's electrical system. Small enough to carry on your bike; designed
to be easy to use on the road or in your garage. Classic Boxer
Charging 2.0 is full of useful graphics and photos, easy to
understand instructions, and color wiring diagrams for Boxers
1969 to 1995.

"Classic Boxer Charging: Self Help
for the Electrically Challenged, BMW Twins 1970-1995 is a winner
- worth owning and reading and hauling around"